The present disclosure relates to a drive unit which includes a vibratory actuator and drives a lens frame.
Conventionally, as a drive unit for driving a lens frame, various drive units have been known. For example, a drive unit according to Japanese Patent Publication No. 2006-067712 (hereinafter referred to as PATENT DOCUMENT 1) includes a vibratory actuator with two actuator bodies each of which is comprised of a piezoelectric element. Specifically, the two actuator bodies are arranged so that a shaft is sandwiched therebetween. The vibratory actuator further includes two engaging members between which the two actuator bodies arranged as described above are sandwiched. The two engaging members are connected together via a housing and are biased by two coil springs in the direction toward the two actuator bodies. That is, the two actuator bodies press on the shaft from both sides. The vibratory actuator configured as described above has a substantially rectangular-parallelepiped shape formed by the actuator bodies and the engaging members. The shaft sticks out from one end portion of the vibratory actuator in the longitudinal direction of the vibratory actuator. When the two actuator bodies are vibrated in this state, drive force of the actuator bodies is transmitted to the shaft, and the shaft is driven in the axis direction of the shaft. An end of the shaft is connected to a lens frame. Specifically, a pin is provided at the end of the shaft to extend in the radial direction of the shaft. A long hole is provided in the lens frame to extend in parallel to the shaft. The pin provided at the end of the shaft fits in the long hold of the lens frame. The pin fitting in the long hole is substantially fixed by a plate spring. Thus, displacement of the shaft in the axis direction is transmitted to the lens frame.